Lifting jack



June 19, 1928. 1,674,397

' A. C. HOPKINS LIFTING JACK Filed April 15, 1927 2 Sheets-Sheet 1INVENTOR m 2 @wmwe A TTURNE VJ June 19, 1928.

A. C. HOPKINS LIFTING JACK Filed April 15, 1927 2 Sheets-Sheet 2INVENTOR ir/fior C. HOP/r076 A TTORNE Ys Patented June 19, 1928.

UNl'FE D STATES PATENT @FFICE.

1 :AETHIUR Gfl-HQPKINS; MICHIGAN, ASSIGNOR TO NATIONAL-STANDARD COM-PANY, OF RIFLES- .JlrIICI-IIGAN.

LIFTING JACK,

Application filed April 15,v

powerful.

Second, to provide an improved lifting jack having friction clutchactuating means in which: theclutch is easily released and at the sametime not likely to slip.

Third, to provide an improved lifting aekhaving these advantages whichmay be rapidly lowered, at the same time the lowering is under thecontrol of the operator.

Objectsi'elatin'g to details and economies of construction and operationof my 11)Vt 31'! tion will appear from the detailed description tofollow.

The invention is defined and pointed out" in the claims.

A structure which is a preferred embodiment of my invention isillustrated in the' accompanying drawing, .forming a part of thisspecification, inwhich:

Fig. 1 is a perspective viewof a lifting jack embodying the features ofmy. invention.

Fig. 1 is adetail perspective view of the outer portion of the actuatinglever.

Fig. 2 is a detailview partially in section?" on line 2-2 of Figs. 3;and 4, showing struc tural details.

Fig. 3 is a detail section on line 33 of Fig.

4 a detail section on line 4L of Fig 1 In the drawing si'milar referencecharacters refer to similar parts throughout the several views.

. Referring to the drawings, the structure il'- lustrated comprises aframe consisting of side members 1, 1 connected in spacedrelation bysuitablecross members. At its rear end, the frame provided with an axle2 for the supportingwheels 3. At the front end of the frame are.laterally projecting brackets 4 on which the caster'wheels v5 aremounted.

The lifting lever 6 is .pivotally mounted on the cross rod 7 extendingbetween the side members.

The head 8 is it-iountedon the pivot 9 on the outer end of the liftinglever. Alink 10 is connected to the head member by the pivot 11 and totheframe by the pivot 12,

the link being disposed in parallel'relation 1927. Serial No. 184,008.

" to the'lifting lever so that as the lifting leveil? is swung on itspivotg the head is'kept in" an upright position.

A- pair of racks 13 are connected to the lifting lever at 14' in spacedrelation to the lever pivot 7. These racks are supported by rollers151onthe frame cross member 16 so that the racks coact with theelongated pinion" 17 having journals 18 in its ends supported on theframe and bearings formed on the brackets 4. On this-*pinion is a clutchdrum 19am also a holding ratchet 20. For

convenience in-nianufature, the drum and ratchet are broached toreceivethe elongated pinion.

' I providea clutch member designated gen erally by the numeral 21' andhaving an annular clutch shoe 22, split at the shoe having a lining orfacing designated by the numeral 24. 'lhe actuating lever 25 is pivotedat 26 on thisclutch- 'inniber-and provided with a thrust member" 27engaging the clutch shoe 22adjacent the split therein. This thrustmember is arranged close to the pivot 26 so that by pressing down uponthe lever, a very powerful leverage is secured to closetheclutch. 2'

v A spring 28 is seated in a holder 29 on the clutch member to engagethe actuating lever 25 at the rear of its pivot 26, as shown inflFig. 3,the spring acting to normally engage the clutch or to urge its shoe toen gag ng position.

An upward, lift, however, on the lever swings the thrust member awayfrom the shoe, thereby releasing t-he'clntching pressure.

: To hold the clutch against rotation and thereby prevent thisreleasing. operation, I provide the clutch member with a segmental rack30 with which a, reversing pawl 31 coacts, [this reversing pawl beingnormally held ininoperative position, as shown in Fig. 3. The holdingpawl 32 coacts with the holding ratchet 20, being held normally inengagement therewithby' the spring 33,

this spring acting also to hold the.pawl 31 out of engagement.

In the lifting. operation, the lever 25 is oscillated to release theclutch and. allow it toswing around the drum for a new grip, the clutchbeing released merely by an upward lift on the lever andcngaged by adownward thrust thereon. Continued downward thrust rotates the drumwhich is held against backward rotation by the nolding pawl coactingwith the lever. hen it is desired to lower the lifting member, thereversing member 34, which is in the forni of an annular rack mounted onthe shoulder 35 of the ratchet, is actuated to disengage the holdingpawl and engage the reversing pawl.

This reversing member 34 is provided wit-h arms 36 and 37, the arm 36carrying a rod 38 which is pivoted at 39 to the arm, the rod beingslidably engaged with the lug 40 on the pawl 31. A coiled spring 41 isarranged between the lug and the shoulder 42 on the rod so that as thereversing member is rotated, the thrust of the spring acts to yieldinglyurge the pawl 31 into engagement with the rack 30, at the same time theholding pawl 32 is released. This pawl is connected to the arm 37 bymeans of the rod 43 which is pivoted to the arm 37 at 44, the rod beingslidable through a lug 45 on the pawl, a spring 46 being arrangedbetween the lug 45 and the thrust collar 47 so that as the member 34 isrotated, the engagement of the pawls is reversed.

When the pawl 31 is engaged, the rotation of the clutch member isprevented. thereby allowing a releasing of the clutch by liftingupwardly on the lever 25, and if desired, the amount of slippingfriction necessary can be maintained to allow the slow return of thelifting lever.

The reversing member is actuated by a dog 48 which is pivoted at 49 onthe link 50. This dog has a rearwardly extending tail 51 to which thecontrol rod 52 is connected. A spring 53 is connected to the dog at 54and to the clutch member at 55, so that by pulling on the control rod,the first action is to swing the dog on its pivot49, bringing the lug 56into engagement with the rack of the reversing member 34; continued pullon the rod rotating the rack, and thereby engaging the reversing pawland releasing the hold:

ing pawl.

The control rod is provided with a hand piece 57 adjacent the hand piece58 of the lever so that the hand pieces may be simultaneously graspedversed and quickly lowered, the lowering being under the control of theoperator. 7

I have illustrated and described my improvements in an embodiment whichI have found very practical. I have not attempted to illustrate ordescribe certain modifications or adaptationswhich I contemplate as Ibelieve this disclosure will enable those skilled in the art to embodyor adapt my improvements as may be desired.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is:

1. In a lifting jack, the combination of a frame, a lifting member, adrum operatively connected to said lifting member, a clutch memberprovided with a rack and with a clutch shoe coacting with said drum, anactusting lever pivoted on said clutch member to coact with said clutchshoe, a spring acting to normally urge the clutch shoe to engagingposition, a holding ratchet connected to said drum, a holding pawlcoacting with said holding ratchet, a reversing pawl coacting with saidrack on said clutch member, a rotatably mounted reversing memberprovided with a rack and with radially disposed arms, rods pivoted tosaid arms on said reversing member, said pawls being provided with lugswith which said rods are slidably engaged, springs arranged on said rodsand acting to release the holdingpawl and engage the reversing pawl onthe actuation of said reversing member, a reversing member actuatingdog, a supporting link for said dog, a spring acting to hold said dognormally in disengaged position, and a control rod connected to said dogwhereby a pull will first engage the dog with the reversing member and acontinued pull will actuate the same.

2. In a. lifting jack, the con'ibinaticn of a frame, a lifting member, adrum operatively connected to said lifting member, a clutch memberprovided with a rack and with a clutch shoe coacting with said drum, anactuating lever pivoted on said clutch member to coact with said clutchshoe, a spring acting to normally urgethe clutch shoe to engagingposition, a holding ratchet connected to said drum, a holding pawlcoacting with said holding ratchet, a revere ing pawl coacting with saidrack on said clutch member, a rotatably mounted revers ing memberprovided with radially disposed arms, rods pivoted to said arms on saidreversing member, said pawls being provided with lugs with which saidrods are slidably engaged, and springs arranged on said rods and actingto release the holding pawl and engage the reversing pawl on theactuation of said reversing member.

3. In a lifting jack, the combination of a frame, a lifting member, adrum operatively connected to said lifting member, a clutch memberprovided with a rack and with a clutch shoe coacting with said drum, anactuating lever pivoted on said clutch member to coact with said clutchshoe, a spring acting to normally urge the clutch shoe to engagingposition, a holding ratchet connected to said drum. a holding pawlcoacting with said holding ratchet, a reversing pawl coacting with saidrack on said clutch member, a rotatably mounted reversing memberprovided with a rack and with raditit) ally disposed arms, a rwrersingmember ac tuating dog. a su n iort ug 'i l; for said d a spring actingto hold said dog iltiliiilillv in disengaged position, and a control rodconnected to s: id dog wher bv a poli will first engage the dog w ith 2hrevcr her and a continued pull will actuate th same.

4. In a lifting: iaclr. th combination f a frame, a lifting member,'lrnni operatiw l v connected to said lift ng membe a cl t hIl'lOl'llllGl provided with a incl: and with a clutch shoe ena t ng withr-nid drum. an n"- tuating lever pivoted on aid hdc'n w mbto enact withsaid clutch shoe, a :-=pring a iing to norinnliv urge the clutch slengaging posit on. a holding ratchet onnect to said drum. a holding pawlcoa ting' v, said holding rat het. a reversing pawl coacting with saidrack on said clutch llit:.-'!- her, and a rotatably mounted r versingmenu ber provided with radiallv dispo d arm;

5. In a lifting jaclt. the combination of a frame, a liftin T membe adrum op rzul've ly connected to raid lifting member. a l"llii"il memberprovided with racl: and with a clutch shoe coactiing with said drum, anactuating lever pivoted on said cluiwh iiltil" her to oact' with saidclut h shoe. :1 spring acting to normally urge the clutch shoe engagingposition, a holding ratchet coir nected to said drum. a hwlding pawloaciing with said holding ratchet, a rcver iug pawl coacting with saidrack on said clut h member, a rotatably mounted rcver inzs memberprovided with a l'tl('l\' operativel v associated witl s id pawl torelease the holding pawl and eng" are the reversing pawl on th*actuation of said reversing il'ltm f. a reversing member ctuating doporting linl; for said dog. a spr to h ld said dog normally in disengzrsition. and a control iod conne ted to sa d dog whereb} a pull with thereversing member and a continued pull will actuate the aaiiie.

ti. In a lifting jaclt. the com ination of a frame. a lifting member, adrum operativelv connected to said lifting member. a clutch memberprovided with a rack and with a. clutch shoe coacting with said drum. anactuating lever pivotcd on said clutch 1nem bcr to enact with saidclutch shoe. :1 sprina' acting to normall'a urge the clutch shoe toengaging position. a holding ratchet connected to said drum. a holdingpawl coacting with said holding ratchet. a reversing pawl coacting withsaid rack on said clutch member. and a rever ing member provided with arack operativelv associated with aid pawl.

T. In a lifting jack. the combination of a frame. a lifting member. adrum operativelv connected to said lifting member. a clutch memberprovided with a rack and with a n in will tir t engage th dog clutchshoe coacting with said drum, an actuating lever pivoted on said clutchmember to coact with said clutch shoe, a holding ratchet connected tosaid drum, a holding pawl com-ting with said holding ratchet, areversing pawl coacting with said rack on said clutch member, arotatably mounted reversing member provided with a rack and operativelyconnected to said pawls whereby the holding pawl is released and thereversing pawl engaged on the actuation of said reversing member, areversing member actuating dog, a supporting link for said dog. a springacting to hold said dog nor mally in disengaged position, and a controlrod connected to said dog whereby a pull will first engage the dog withthe reversing member and a continued pull will actuate the same.

8. In a lifting jack, the combination of a frame. a lifting member, adrum operativel v connected to said lifting member. a clutch memberprovided with a rack and with a clutch shoe coacting with said drum, anactuating lever pivoted on said clutch member to coa t with said clutchshoe, a holding ratchet connected to said drum, a holdin pawl coactingwith said holding ratchet, a reveiudng pawl coacting with said rack onsaid clutch member, and a reversing member operativelv connected to Saidpawls v-Jhercby the holding pawl is released and the reversing pawlengaged on the actuation of said reversing member.

5). in a lifting jack, the combination of a frame, a lifting memberpivotally mounted on said frame, a pair of rack bars pivotally connectedto said lifting member in spaced relation to its pivot, an elongatedpinion coacting with said rack bars, a drum on said pinion, a clutchmember provided with a racl; and with an annular split clutch shoecoacting with said drum, an actuating lever pivoted on said clutchmember to coact with one end of said clutch shoe. a spring interposedbetween the opposite end of said clutch shoe and said lever and actingto normall v urge the clutch shoe to engaging position, a holdingratchet connected to said pinion. a holding pawl mounted on said frameto coaci with said holding ratchet, a reversing pawl mounted on aidframe to coact with said ra l; on said clutch member, and a reversingmember operativcly associated with said pawls.

ll. ln a lifting jack. the combination of a frame. a lifting memberpivotally mounted on said frame. a pair of raci: bars pivotallyconnected to said lifting member in spaced relation to its pivot, anelongated pinion coacting with said rack bars. a drum on said pinion, aclutch men'iber provided. with a rack and with an annular split clutchshoe coacting with said drum, an actuating lever pivoted on said clutchmember to coact with said clutch shoe, a holding ratchet connected tosaid pinion, a holding pawl mounted on said frame to coact with saidholding ratchet, a reversing pawl mounted on said frame to coact withsaid rack on said clutch member, and a reversing member operativelyassociated with said pawls.

11. In a lifting jack, the combination of a frame, a lifting memberpivotally mounted on said frame, a rack bar pivotally connected to saidlifting member in spaced relation to its pivot, a pinion coacting withsaid rack bar, a drum connected to said pinion, a clutch member providedwith a rack and with an annular split clutch shoe enacting with saiddrum, an actuating lever pivoted on said clutch member to coaet with oneend of said clutch shoe, a spring interposed between the opposite end ofsaid clutch shoe and said lever and acting to normally urge the clutchshoe to engaging position. a holding ratchet connected to said pinion, aholding pawl mounted on said frame to coact with said holding ratchet, areversing pawl mounted on said frame to coact with said rack on saidclutch member. and a reversing member operatively connected to saidpawls whereby the holding pawl is released and the reversing pawlengaged on the actuation of said reversing member.

12. In a lifting jack, the combination of a frame, a lifting men'iberpivotally mounted on said frame, a rack bar pivotally connected to saidlifting member in spaced relation to its pivot, a pinion enacting withsaid rack bar, a drum connected to said pinion, a clutch member providedwith a rack and with an annular split clutch shoe coacting with saiddrum, an actuating lever pivoted on said clutch member to coact withsaid clutch shoe. a holding ratchet connected to said pinion. a holdingpawl mounted on said frame to coact with said holding ratchet, areversing pawl mounted on said frame to coact with said rack on saidclutch member, and a reversing member operativclv connected to saidpawls whereby the holding pawl is released and the reversing pawlengaged on the actuation of said reversing member.

13. In a lifting jack. the combination of a frame, lifting member. adrum operativelv connected to said lifting member. a clutch memberprovided with a rack and with a clutch shoe coacting with said drum, anactuating lever pivoted on said clutch member to coact with said clutchshoe, a spring acting to normally ur 'e the clutch shoe to engagingposition, a houling ratchet connected to said drum. a holding pawlcoacting with said holding ratchet. a reversing pawl. coacting with saidrack on said clutch member. and a reversing member operatively connectedto said pawls to release the holding pawl and engage the reversing pawlon the actuation of said rcversing member.

14. In a lifting jack, the combination of a frame. a lifting member. adrum operatively connected to said lifting member, a clutch memberprovided with a clutch shoe coacting with said drum, an actuating leverpivoted on said clutch member to coact with said clutch shoe, a holdingratchet connected to said drum, a holding pawl coacting with saidholding ratchet, :1 reversing pawl coacting with said clutch member, anda reversing member operatively connected to said pawls to release theholding pawl and ei'igagc the reversing pawl on the actuation of saidreversing member.

15. ln a lifting jack, the combination of a f ame. a lifting member, adrum operatively connected to said lifting member, a clutch membercoacting with said drum, an actuating lever operatively associated withsaid clutch member, a holding pawl for said drum, means operativclvassociated with said clutch, permitting the releasing of the clutch bymanipulation of said actuating lever, and means for actuating suchreleas ing means operatively connected to said holding pawl whereby theholding pawl and said releasing means are alternately engaged anddisengaged.

16. In a lifting jack, the combination of a frame a lifting member. adrum operativelv connected to said lifting member, a clutch membercoacting with said drum, an actuating lever operativclv associated withsaid clutch member. a holding means, clutch releasing means, and meansfor actuating such releasing means operativelv connected to said holdingmeans hercbv the holding means and said releasing means are alternatelyengaged and disengaged.

In witness whereof I have hereunto set my hand.

ARTHITR C. HOPKINS.

